Struct Budget 

pub struct Budget { /* private fields */ }

Shared between an engine’s runtime and its interrupt handler.

Records why execution was interrupted rather than leaving it to be inferred from the engine’s own exception or trap text. QuickJS, for instance, reports an interrupt as an ordinary Error whose message happens to be “interrupted”; keying behavior off that string would make the difference between “your rule looped forever” and “your rule threw” depend on wording this project does not control. A different engine’s own interrupted-execution signal would be exactly as unreliable to string-match, for the same reason.

Implementations

impl Budget

pub fn new(clock: Arc<RunClock>) -> Arc<Self>

Build a budget enforcer sharing the run’s clock.

pub fn arm(&self, rule_timeout: Duration)

Start the clock on one invocation.

pub fn disarm(&self)

Stop enforcing an invocation budget.

pub fn pause(&self) -> Paused<'_>

Stop charging the current invocation while the host does work on its behalf.

Returns a guard; the invocation resumes with exactly the time it had when the guard was taken, measured from wherever the run clock is when the guard drops.

Why not disarm followed by arm

Budget::arm takes a fresh rule_timeout and also clears Budget::take_trip’s record. Re-arming after a provider call would therefore hand the rule a whole new allowance on every question it asks — a rule asking a hundred type questions would be bounded by nothing — and would erase a global-budget trip that had already been recorded, turning a run timeout into silence. This carries the remainder instead, so a rule’s own budget still bounds a rule’s own code and nothing else.

The global check at Budget::should_interrupt is untouched: a paused invocation is still inside a run, and a run that has overrun must still stop.

Nesting composes rather than being forbidden, which costs no runtime check: an inner pause reads an already stopped clock as disarmed and so restores nothing on drop, leaving the outermost guard — the only one holding a real remainder — to resume.

pub fn should_interrupt(&self) -> bool

Whether execution should stop now, recording why. Called by the engine’s interrupt handler, so it runs often and must stay cheap.

pub fn take_trip(&self) -> Option<Trip>

Which budget was breached, if any. Clears the record.

pub fn clock(&self) -> &RunClock

The run clock this budget was built from.

Trait Implementations

impl Debug for Budget

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.